Aruma Resources has intersected multiple pegmatites over a 1500m strike length in its latest drilling at the Mt Deans lithium-rubidium project. RC drilling was conducted over the pegmatite swarm where previous drilling returned grades up to 1.14 per cent lithium and 1.05 per cent rubidium. The company says current drilling intersected visual lithium mineralisation identified as the mineral lepidolite.
The presence of lepidolite is important because the conversion of lepidolite to lithium hydroxide takes place at approximately one quarter of the cost per tonne when compared to lithium hydroxide production from spodumene. Rubidium is commonly found in lepidolite and has the potential to add considerable value as rubidium carbonate currently sells for over US$1,000 per kg with prices up to five times more for high purity products. This works out to a mind-blowing figure of over $1 million per tonne.
Aruma’s infill and extensional RC drilling program comprised of 15 holes for 1,560m with depths between 80m and 120m per hole. The company said the latest exploration extended the lithium and high-grade rubidium mineralisation defined in the first phase of drilling and surface rock chip sampling. The company says sheeted vein pegmatite hosted mineralisation remains open at both ends.
Historical drill chips throughout the project area have been resampled by Aruma to assay for the full lithium suite of elements. The company found pegmatitic material and identified lepidolite in some of the material, adding further excitement. The eagerly awaited assays from historical and current drilling will guide the next phase of drilling.
The Mt Deans lithium-rubidium project is located near Norseman, in the lithium corridor of south-eastern Western Australia. The area hosts significant deposits such as Mt Marion, 51.4Mt going 1.45 per cent lithium oxide, Bald Hill, 26Mt grading 1.0 per cent lithium oxide and Buldania, 14.9Mt at 1.0 per cent lithium oxide. Aruma states that its Mt Deans pegmatites sit within the same host rocks and structures as the other notable lithium deposits.
Management believes the sheeted pegmatite vein package at Mt Deans includes solid veins to 25m thick which compares to Buldania where average vein thickness is 4-9m in an average 26m vein package. The presence of rubidium at Mt Deans is also a point of difference with these other lithium deposits and adds a multi-commodity focus for Aruma.
At nearby Mt Marion a current upgrade project is underway to increase production to 900,000 tonnes of mixed grade spodumene concentrate per annum by December 2022. The price for this 6 per cent lithium spodumene concentrate has tripled to US$6,000 from US$2000 per tonne from January 2022 to July 2022 according to the latest presentation from Mineral Deposits, the owner of the Mt Marion mine.
Aruma appear well positioned in a noted lithium corridor with the potential to build a multi-commodity lithium-rubidium resource. The notable presence of lepidolite in current drilling and historical drill chips augurs well for possible low-cost metallurgical processing should resources be proven through further drilling.
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By Matt Birney
